The objective of this study is to determine thresholds and dose-response relationships for the effects of 27-MHz radiofrequency rediation (RF) on mammalian somatic and germ cells in vitro under accurately measured and precisely controlled exposure conditions. The extent to which said effects are dependent upon RF frequency will be determined by comparision with the effects of other RF frequencies, specifically 1-, 10-, 50- and 100-MHz. The rationale for this study is to provide data to be used in the assessment of potential health risks associated with occupational exposure to 27-MHz RF radiation generated by RF heat sealers, diathermy equipment and other devices that are known sources of human exposure. Since such devices are generally operated intermittently, comparative studies will be conducted of continuous wave and amplitude modulated 27-MHz RF. Well-characterized somatic cells (erythrocytes, neutrophils, glioma [C5 and LN-18], fibroblasts and HeLa) and germ cells (mouse ova and sperm) will be exposed under conditions of accurately measured electric and magnetic field strength in a temperature-controlled coaxial line RF cell exposure system. The dependent variables will include: 1) cell viability and morphology, 2) phagocytosis and chemotaxis, 3) plasmalemma cation permeability 4) cell cycle regulation, 5) DNA and protein synthesis, 6) sperm viability and motility, and 7) fertilization (in vitro).